The present invention relates to the isolated cDNA sequence encoding amarandin-S, eukaryotic ribosome-inactivating protein (RIP) having antiviral activity, which is present in Amaranthus viridis, to the expression vector containing said cDNA sequence and to a host transformed by said vector.
An interesting recent development is the discovery of plant proteins that have prophylactic effects against viruses. According to Antiviral Compounds from Plants, 1st ed., CRC Press, Inc., (1990), ribosome-inactivating proteins (RIPs) are plant toxins, classified as type 1 and 2, having antiviral and abortifacient activities with N-glycosidase activity on ribosomal RNA sequence. Interest in ribosome-inactivating proteins stems from their potential utilization in medicine and agriculture, due to their antiviral and antifungal activities. Also, efforts have been made either to inhibit virus replication comprising virus-induced human diseases, like HIV-1 replication, selectively in cell cultures or to custom design extremely specific and very effective small peptide conferring an antiviral activity to interfere with the penetration stage of certain myxoviruses.